Rotary steam engine



Nov. 5, 1940. v. c. LYNCH ROTARY STEAM ENGINE Filed May 26, 1939 3 Sheets-Sheet 1 5 5 6 4. 4 W w l! 07 y d ,4 2 2 w a @f 5 .A/U 2B qui IMIIV 2 n 4l wwvlnnuu. W w will: 4 wvl 4 ,i mfr.' Jl 5 m 23, n y 4 a 3 Nov. 5, 1940. v. c. LYNCH 2 ROTARY STEAM ENGINE Filed May 26. 1939 3 Sheets-Sheet 2 v Patented Nov. 5, 1940 PA'ri-:lv'rv OFFICE 2,220,375. y ROTARY STEAM ENGINE Vernon C. Lynch, Western Springs, Ill., assignor cfl iifty per cent to Robert Bean, Brookfield,

Application May 26, 1939, Serial No. 275,935

9 Claims.

This invention relates to vrotary steam engines and-particularly to improvements in the engine construction, in the arrangements for admission ,and exhaust of steam and the means for con- 5 Ytrolling the engineV operation.

The main objects of this invention are to provide an improved steam engineof the rov tary type wherein the inexpansive force of steam .is applied tangentially at the periphery of an annular driven member; to provide such a device wherein the reactive force of admitted steam is utilized in addition to the expansive power of the steam; to provide a rotary steam engine having an improved arrangement of steam inlet and exhaust; to provide Vsuch a device having improved means for controlling the cut-off of steam admitted to the expansion chamber; to provide a rotary steam engine having improved and simplified valving mechanism and arrange- 'ment; to provide a rotary steam engine having an improved arrangement and construction for the cylinder head gates; to provide an improved and simplied arrangement for control and actuation of the cylinderhead gates of a rotary steam engine; to provide a rotary steam engine having an improved housing construction; and to provide a simplified rotary steam engine construction. wherein the number of moving elements are reduced to va minimum and whereby more eiicient operation is obtained. A specific embodiment of this inventionfis shown in the accompanying drawings in which:

Figure 1 is a view showing the device in crosssectional end elevation.

substantially line 2-2 of Fig. 1.

Fig. 3 is a View of the gate control cam as taken on line 3-3 of Fig. 1. Y d Fig. 4A is a view as taken on line 4-4 of Fig. 1,

the gate actuating cam shown in Fig. 3.

Fig'. 5 is a sectional view as taken on line 5--75 of Fig. 2, showing the arrangement of cylinder head gates.

Fig. 6 is a diagrammatic view showing the piping and steam supply control valve arrangement.Y n

Fig. '7 is `a sectional view taken on line 1 1 of Fig.l 2 and 5H taken from the line 8-8 of Fig. 7.

In the form shown in the drawings, my improved rotary steam engine comprises an annular hollow casing formed of two bell-shaped half-sec- D" tions I set `face-to-face and bolted together along Fig. 2 is a partially sectioned view as taken on rshowing the reversing mechanism for controlling Fig. 8 is a fragmentary View of the same asl their annular peripheries to form a hollow interior within which a disc-like fly wheel or crank element 2 is mounted on a rotatable shaft 3 extending through the casing on the central axis n of the same; the shaft 3 being supported on bearings 4 mounted centrally in the walls of the half sections l and, as shown, being fixed against axial movement relative to the engine casing by lock nuts 5 threaded onto the shaft 3.`

As shown, the central, portions of the casing half-sections I are substantially bell-shaped so as to provide a somewhat spherical central cavity within the casing and the margins of the bellshaped portions extend radially outward to terminatein bolting flanges 6 where the two halfsections meet and are joined.

These radially-extending casing portions, between the flanges 6 and the bell-.shaped portions, are spaced from each other and shaped to provide a pair of concentric annular channels.l The 2 first or innermost channel is a straight walled space communicating with the central cavity and into which the margin of the `flywheel or crank element 2 extends. The ysecond channel, which surrounds the rst channel, has outwardly curved sidewalls formed to provide a continuously annular peripheral piston chamber 1, having a circular ycross section within which are disposedy arcuately cylindrical piston members 3 carried on the periphery of the flywheel or crank member 2.

lThe flywheel 2, which is keyed to the shaft 3 by means of a key 9, is proportioned so that its periphery willbe substantially tangentialwith the inner side of the annular peripheral chamber 1, and the piston members 8, which are designed to fit the annular peripheral chamber 1, are fast on the periphery of the ilywheel 2, preferably being formed integral therewith.V

As shown, the pistons 8 are` two in number and are diametrically disposed on the periphery of the iiywheel 2 so that in rotation of the flywheel the pistons travel angularly in the chamber 1. Also, the chamber 1 is divided into three equal arcuate segments by means of shiftable gate members I0 which extend into the annular chamber 1 from each side of the casing and which are arranged to be opened to allow a piston to pass and then be closed to provide a head against which steam admitted into the chamber 1 may expand and exert its force between the piston and the closed gates to cause rotation oi the flywheel 2.

A particular featureof my invention is the manner and arrangement by which steam is supsteam passages serves as a steam chest and ther other passage serves as an exhaust steam receiver.

first becomes an exhaust receiver and the other becomes the steam chest.

As shown, these steam passages II and I2 are enclosed except for arcuate ports I3 and I4, re# spectively, located in the inner side wall of the respective intermediate portions of the casing half-sections and through which the steam passes on its way to and from the peripheral expansion chamber 1 in which the pistons 8 are housed. v

Communication between the peripheral expansion chamber 'I and the ports I3 and I4 is provided by passages I and I5 which lead from the margins of opposite faces respectively of the fly wheel 2 at the same radial distance from the central axis as the ports I3 and I4, and pass through the body of the .y wheel into the body of the piston 8, where they terminate at respective opposite ends of the piston. Thus, steam from the stearnpassage I2 will pass through the port I4 and the fly wheel passage I6 and into the expansion chamber .'I, being discharged from the center of the rearward or following face of the piston; and steam being exhausted from the expansion chamber I will ienter the passage I5, opening into the leading face of the piston, passing therethrough to the annular passage II- from which it is suitably dis-l charged or removed as Will be later described.

The ports I3 and I4 extend angularly along the inner side wall of the respective casing intermediate portions and a pair of such ports is provided for each segment of the peripheral chamber "I, dened by the shiftable gates IS, asl

indicated in Fig. 2 of the drawings; these ports, in the form shown, being approximately 70 to 80 degrees in effective arcuate length and located between the positions ofthe gates I D. The ports of the respective casing half-sections are, however, not in registrywith each other, those of one side or half-section being advanced with respect to those on the opposite side in thedirection of fly wheel rotation, so that the ports on the exhaust side will be nearest the gate toward which the piston is movingy and the ports on the steam intake side will be nearest the gate against which the incoming steam is being expanded.

This is accomplished by locating the ports for each peripheral segment so that in one cas.- ing half section the respective port Will begin near the gate at one end of the segment andV extend arcuately therefrom toward the other end, while the port in the opposite casing half section will begin adjacent the said other end and extend backward, arcuately, toward the rst mentioned segment end.

In this way the ports on either side of the y wheel 2 will be uniformly spaced with regard to the gates and regardless of the direction Upon reversal of the engine rotation the function of these passages is reversed and the plied to the piston chamber 'I and by which the of y wheel rotation the valving will be the same since the steam side will be the side having the ports first approached by the piston as it passes the gates.

Thus, in the three-segment arrangement shown, each casing half-section will have an inside face view like that shown in Fig. 2 wherein the front or leading end of each port is located approximately `l0" inside of the entering gate, assuming the piston'to be traveling clockwise as viewed from the inside face side of the halfsection casing, or so that the entering end of the` steam passage I6 located on the face of the y Wheel 2 will be about one-quarter open as thegate begins to close and in full registry with `the port when the piston has moved to the point where the gate is entirely closed.

In the form shown valving of the steam ports I3 and yI4 is accomplished by means of a pair of `flat annular ring-like valve plates or rings I'I and. I8 arranged to lie flatly against the inner faces of the engine casing half-sections, one on each side ofthe Iiy wheel 2. These valve rings are "formed to fit the inner faces of the halfsections and close the space between the inner walls of the half-sections and the side walls of thev fly Wheel 2, the fly wheel sliding between the valve rings which are normally stationary, and the inner margins of the valve rings extend'into the spherical central cavity of the engine casing where each ring is offset away from the fly wheel as at I9 to provide a pair of shoulders and 2|. The shoulder 20 is formed to fit the inside margin of the bell-shaped portion of the engine casing and the shoulder 2I- is arranged to t against a complementary shoulder of the y wheel 2 so that each valve ring will be securely held in its proper position relative to the concentric ring of ports in the inner walls of the casing sections.

Also, the inner periphery of the offset portion I9 of each ring is provided with gear teeth 22'u for coaction with gears `23 and.` 24, one for each Vvalve ring, which in Lturn are respectively mounted fast on operating shafts 25 and 26 extending into the casing from reach side thereof. Each of these operating shafts extends through the respective casing side wall and is suitably journalled therein as indicated in Fig. l, the outward end of each shaft being provided with suitable means`21 by which each shaft may be independently rotated.

Each of the valve rings I'I and I8 vis provided with steam ports 28 and 29, respectively, of the same size, angular spacing and radial location as the effective area of the ports I3 and I4 in the casing half-sections and since the valve rings are positioned between the casing half-sections and the fiy wheel 2, the angular position at which steam cut-olf is desired and the location at which exhausting is to begin may be readily adjusted by merely shifting,` the valve rings angularly by means of the operating gears 23 and 24 and shafts 25 and 26. Thus quick and accurate control will be had. Also, if desired, the means 2`I may be arranged to be operated from a governor, not shown, in a manner that will be readily understood by those skilled in this art though such arrangement is not illustrated herein.

The valve rings I'I and I8 are also provided with means to prevent them from springing outward toward the y wheel 2 when under the influence o-f steam pressure While serving as cut-ofi` elements on the steam pressure side of the engine, These means are illustrated in Figs. '7

i faces of the steam passages II and I2 adjacent the respective port openings I3 and I4. As

shown, the shoes 20.I are small substantially rectangular plates having upper and lower tongues 20.3 arranged to fit into the grooves 20.2 which plates are fastened to the inner or casing side of the valve plates at the end toward which the piston is moving when the valve plate is serving as a control for incoming steam.

In order to accommodate the shoes 20.I when the valve plate is in full open position, the steam ports I3 and I4 are made longer than the desired effective length by an amount equivalent to the length of the shoes. Thus the presence of the shoes does not decrease the desired working length or area of the steam port. The shoes 20.I do, however, provide support for those portions of the valve plates which are under steam pressure when the valve plates are moved or advanced to shorten the point of cut-off or the period of steam admission, thus preventing binding between the valve plate and the ily wheel on the pressure side.

Also as shown suitable annular gaskets or sealing rings 20.4 are provided, between the engine casing and the valve rings, above and below the steam ports to prevent leakage of steam between the valve plates and the inner face surfaces of the casing.

The gates I0, which divide the annular chambers 1 into the segments which serve as the cylinders of this device, are arranged in pairs, there being one pair for each segment dividing line. As shown in Fig. 5, these gates are rectangular plates which extend through the side walls of the casing half-sections, through suitable openings 30 therein, and meet at the center line or axis of the annular chamber 1. As shown, the gate plates I0 are preferably of tapering width, the narrowest part being the meeting edges of the gates and the widest part being the gate portions which project outwardly from the casing side walls. The purpose of this tapering arrangement is to provide a tight t between the gate and the casing side wall aperture, when the gates are in closed position, and to compensate for wear. Also, as shown the meeting edges of the gates are provided with a tongue and groove arrangement so as to assure tight closure and obviate leakage of steam between the gates during the period of steam expansion. Thus, one gate is provided with a tongue 3I on its inner edge and the other gate is provided with a complementary groove 32 on its inner edge.

As shown in Fig. 1, each of the gates I0 is operated by a bell crank lever 33 which pivots about a pivot pin 34 suitably mounted in a boss on the outside of the respective casing half-section at a suitable point on the bell-shapedv portion thereof. One arm 35 of the bell crank 33 extends through a slotted opening in the bellshaped portion of the casing half-section into the interior thereof where it is engaged by actuating means that will be hereafter described. The other arm of the bell crank extends radially along the outside of the engine casing toward the gate to which it is pivotally fastened by means of a suitable pin 36.

The bell crank arm 33 is normally held in a position close to the outer side wall of the casing lhalf-section, or so that the gates I0 are in closed position, by means of a looped spring 31 which is supported by the bell crank pivot pin 34 and which has one leg extending over the radially projecting portion of the bell-crank 33, and which has its other leg bearing against the side wall of the engine casing. This spring 31 is of suitable tension so that it will serve as the actuating means to close the respective gate I0 and hold it normally in a closed position.

The means for actuating the bell crank 33 to open the gates comprise a pair of cams mounted fast onthe shaft 3 and located one on each side of the flywheel 2. These cams in their rotation with the shaft 3 actuate a plurality of levers 38 which are suitably mounted pivotally on the inside of the bell-shaped portion of the engine casing and arranged to lie in plane parallel with the fly wheel 2. The arms 38 are spaced angularly around the interior of the central cavity of the engine casing and one arm is provided for each bell crank 33. These arms are actuated by the cam arrangement carried on the shaft 3 so as to move in a radial direction relative to the shaft 3 under the influence of the said cam.

Also, as shown in Figs. 1 and 3, the arms 38 are arranged so that the arm 35 of the respective bell crank 33 will rest against the outer end surface of the arm 38, thus as the varm 38 is shifted radially outward by the actuating cam it will in turn actuate the Abell-crank 33 so as to cause the respective gate to be withdrawn from the cylinder chamber 1. As shown, the arms 38 are relatively long members and their pivot points 39 are located in bosses formed on the inside of Y the bell-shaped portion of each casing half section, the locus of the pivots being on a circle of substantially the same diameter of the valve plate gear 22.

The cams which control the operation of the gates I0 are illustrated in Fig. 3 and are particularly designed to permit reversal of the direction of rotation ofi the engine fly wheel and, as shown, comprise a collar 40 having a pair of oppositely-disposed radially projecting flangelike wing portions 4I located at the inner end of the collar. A ring-like cam plate 42 likewise having opposed radially-projecting flange-like Wing portions 43 is then mounted on the collar 40 and a cover plate 44 having flange-like wing portions 45 identical with the wing portions 4I is suitably'fastened to the other end of the collar 40. The wing portie-ns 4I and 45 are thus spaced apart and in the space between them the cam ring 42 is held.

As shown, the collar 40 is made fast to the shaft 3 by means of headless set screws 46 and the cam ring 42 is loose on the collar 40, however, movement between the cam ring 42 and the collar 40 is controlled by means of a pair of segment-shaped keys 41 each of which is mounted in a square aperture 48 formed in a respective one of the radially-projecting wing portions 43 of the cam ring 42. Each of the keys 41 is provided with anintegral shaft 40 which has one end journalled in the wing portion 4I and which has its other end extending through and projecting beyond the wing portion 45, the location of the shaft 49 being in each case on the radial center line of the respective wing portions.

Also as shown in Figs. 1 and 3 each of the keys 41 is provided with a spring 41.I disposed in an aperture through the key body so as to bear against the two lateral wings 4I and 45, thus providing a friction means to prevent undesired shifting of the key under impact on the camming surfaces of the cam assembly.

The outwardly-projecting portion of each of the key shafts 49 carries a gear 50 fast on its 5 outer end which gear is meshed with a ring gear 5| loose on the shaft 3. The ring gear 5| is held against axial movement relative to the shaft 3 by means of a thrust collar 52 and thus during rotation of the shaft 3 the cam assembly 40, 42 and 44 is rotated with the shaft carrying with it the key 41 and its gear 58, together with the ring gear 5| which is loose on the shaft 3.

As shown in Fig. 3, the wing portions 4| and `45 of the cam members 40 and 42 have side sur- -faces which extend radially from the axis of the shaft 3, and curved end surfaces which are portions of a circular arc having its center at the axis of the shaft 3. Also the projecting wing `portions 43 of the cam ring 42 have end sur- `faces curved along the same circular arc as the end surfaces of the wing portions 4| and 45, but the sides of the portions 43 spread outwardly as they approach the shaft 3` instead of inwardly as the case would be if they were radial with respect to the vvaxis of the shaft 3. The key 41 and the aperture 4B within which it is disposed are so formed that by turning the key by its shaft 49 it will cause the cam ring 42 to shift angularly mon the collar and thereby shift the position 3^of the wing portions 43 angularly With respect to the wing portions 4| and 45, thereby throwing the wing portions 43 toward one side or the other of the wing portions 4| and 45. Also, as nshown, the outermost corners of the wing por- 35 "tions 4| and 45 are cut off so as to coincide with the respective sides of the Wing portion 43 when the cam ring 42 is thrown from side to side under the influence of the key 41.

Thus, the side surfaces 52 of the wings 43 serve :as cam surfaces on which the contacting ends 53 of the levers 38 will ride as they follow the surface of the cam ring 42 to reach the curved ends of the wing portions 4| and 45, at which position the levers 38 are swung to their greatest ldistance radially from the axis of the shaft 3 and at which position the gates I0 are fully open. The length of the are or cam surface on the ends of the wings 4| and 43 determines the time period duringwhich the gates I0 are held in "their fully opened position and is therefore proportioned to permit the piston 8, on the periphery of the fly wheel 2, to fully pass the gate position before the gates are allowed to close, which occurs when the head 53 of the lever 38 reaches `the end of the curved surfaces of the wings 4| and and drops off the same onto the body portion of the camming ring 42.

It will now be seen that .when the camming ring 42 is shifted angularly to the left of the position shown in Fig. 3, by means of the key 41, that the camming mechanism will then be in position to operate the levers 38 when it is rotating in a counterclockwise direction as Viewed in Fig. 3. It will be understood, however, that the angular position of the cam mechanism on the shaft 3 with respect to the position of the pistons 8 will be such that the timing of the operation of the gate actuating means will permit the piston to pass completely through the gates without ever touching the same, the gates beginning to open as the piston approaches, being fully open when the piston reaches the gate position and closing substantially instantly as soon as the piston has fully passed the gate position.

'Ihe angular shifting of the position of the cam ring 42 on the collar 40 is effected by rotating the ring gear 5| relative to the shaft 3 and hence relative to the cam assembly, which rotation causes rotation of the gears 50 carried on the key shafts 49, so as to cause angular swinging of the key 41 which in turn, operating in the opening 48 in the cam ring wings 43, causes shifting of the cam ring 42 through coaction of the key 41 and the sides of the key opening 48.

Shifting of the ring gear 5| is effected by means of a rack 54 having a set of teeth 55 arranged to engage and be meshed with the teeth of the ring gear 5|, the rack 54 extending transversely through the engine casing to the outside thereof where it may be connected with manual or automatic operating means, not shown. A rack 54 is provided for each cam mechanism assembly and the two racks provided in the device illustrated in Fig. 1 are preferably connected on the outside of the engine for simultaneously operating in a manner not shown.

'I'he number of teeth in the group 55 on the rack 54 is such that upon lateral shifting of the rack in the appropriate direction the ring gear 5| will be turned, relative to the shaft 3, a predetermined distance such as to impart the desired extent of rotation of the key gears 49. Thus, upon shifting of the rack 54 so that the teeth 55 are moved to the position shown in dotted outline at 56, the cam mechanism will be reversed and return of the rack teeth to their first position will reset the cam mechanism to its original condition. It will be understood, of course, that the operation of this reversing mechanism will be done only when the engine fly wheel has completely stopped rotation and appropriate means, not shown, may be provided, if desired, to prevent shifting of the rack 54 while the engine is in operation.

As shown in Figs. 1 and 6, steam supply and exhaust connections 51 and 58 are provided for the annular steam passages and |2 respectively, in the engine casing half-sections. The connections 51 and 58 leading to a four-way valve 59, shown in Fig. 6, which provides communication with a steam supply line 60 and a steam exhaust line 6|. Thus,v reversing of the steam flow through the engine may be had by merely turning the four-way Valve 59 through 90 in either direction and shifting the rack 54 in the appropriate direction. Preferably the rack 54 is suitably linked, in a manner not shown, to the valve 59 so that the two will be shifted simultaneously, thus obviating inadvertent operation of one without operation of the other.

Due to the fact that exhaust steam, having become expanded requires a greater outlet area than inlet area it is necessary to provide auxiliary exhaust ports in each of the casing half-sections in order to make the engine perfectly reversible. Thus, as shown in Figs. 1 and 2, lateral ports 62 are provided at each end of each segment of the annular passage 1.

These exhaust ports are provided in each of the casing half-sections and lead through suitable bosses 63 formed on the outside of the engine casing. Also, each of the ports 82 is provided with a gate 64 which gates may be tied together for simultaneous operation in any desired convenient manner, not shown, the arrangement however being such that all the ports 62 at the end of each cylinder or segment toward which the piston is moving, in passing from end to end of the segment, will be open so long as the piston is moving in that direction; the ports 62 at the other ends of the segments being closed until the engine is reversed when the first mentioned ports will be closed and the others opened. Thus, the steam passages II and I2 in the engine half-sections may be of the same size and the steam passages I5 and I6 through the fly wheel 2 and the piston 8 may likewise be of the same size, the increase in exhaust port area being provided by the auxiliary outlets 82. Also, the operating means for the gates B4, though not shown, is preferably linked to the means for operating the rack 54 and the four-way valve 59 for simultaneous operation therewith.

As shown in Figs. 1 and 6, the entire engine is enclosed in a closed jacket 65 which provides a surrounding chamber into which exhaust steam passing through the openings 62 and through the openings for the gates I0 may pass, thus serving to keep the entire engine warm for more eflicient operation and further to provide lubrication for the moving parts on the outside of the engine casing through the medium of oil entrained in the exhaust steam. This function of the exhaust steam is further enlarged by leading the exhaust connection BI from the four- Way valve 59 directly to the interior of the jacket 55, final exhaust from the jacket being had by way of a connection 69 which may lead to a steam receiver or condenser, or to atmosphere.

In operation, assuming the engine iiy wheel to be rotating clockwise as viewed from the righ*- hand end of the shaft in Fig. 1 and the annular passage I2 to therefore be serving as a steam chest, steam will be emitted into the respective segment-cylinder 1 from the annular passage I2 by way of the steam-passage port I4, the valve disc port 29 and the fly wheel piston passage II, as the piston completes its movement past each 440 one of the gate positions; such steam passing through the passage I6 to the center of the piston 8 from which it is discharged out the rearward or following face of the piston.

As shown in Fig. 2, wherein the port I4 leading from the annular steam passage I2 and the port 29 in the valving disc I8 are shown in registry with each other, the opening to the passage I6 begins to meet theA port 29 just as the piston passes the gates I0, being about one-fourth open as the gates begin to close and being in full registry with the port 29 when the gates I0 reach their fully closed position. From then on steam is discharged through the rearward face of the piston until the cut-off position of the valve disc I8 is reached beyond which point the volume of steam supplied to the cylinder expands to further exert its force on the piston 8.

It will now be observed that as the steam is discharged from the piston 8 the reactive force of the steam leaving the piston face will be added to the expansive pressure to drive the piston on its way through the segment-shaped cylinder. Thus, an additional effect of the steam is utilized and the eiiciency of the engine is enhanced, the

reactance force being of considerable benefit because of its point of application and the leverage obtained with respect to the driven shaft 3.

Exhausting is accomplished through the forward or leading face of the piston and also through the auxiliary ports 62 located at the end of the segment-shaped cylinder toward which the piston is moving. Thus, as the piston travels through the segment-shaped cylinder, expanded steam that might be in the cylinder in front of the piston passes through the passageway I5,

opening into the leading face of the piston and thence through the port 28 in the valve ring I1 and the Vports I3 leading to the annular exhaust steam passage II which is on the opposite side of the fly wheel from the steam chest passage I2. That portion of the exhaust steam passing through the auxiliary outlets E2 is discharged directly intothe interior of the jacket 65 surrounding the engine and the exhaust steam fromthe passage II passes, therefrom through the steam pipe 51, valve 59 and the pipe 8| into the interior of the jacket 65, all o-f the exhaust steam being nally removed from the jacket 65 by way of the outlet 66.

As shown, the exhaust passage I5 from the leading face of the piston 8 comes into registry with the exhaust port 28 of the valving disc I'I on the exhaust side of the fly wheel just after the steam inlet passage I6 comes into fully registry with the port 29 of the valving disc I8 so that there will be no back pressure against the forward movement of the piston 8. Also, it will be observed from Fig. 2 that steam enters the segment-shaped cylinder through the passage I6 before the gates I0 are fully closed,rthus preventing the piston from momentarily pulling a vacuum on its rearward side.

In the form shown each p-iston 8 is subjected to three power impulses during each cycle of revolution of the iiy wheel 2 and since two oppositely-dispo-sed pistons are provided, there Will be a total of six power impulses imparted to the fly wheelduring each revolution of the same, each piston going through a cycle of steam admission, expansion and exhaust during its passage through each segment of the annular peripheral passage 1, and the gates ID being automatically opened and closed to allow the piston to pass and to provide a head against which the steam may be expanded as each piston 8 passes the gate positions.

The gates I0 are actuated by means of the two cam assemblies, comprising the parts 49, 42 and 44, through the medium of the arms 38 shown in Fig. 3, and the bell cranks 33 shown in Fig. l, the bell crank for each respective gate being actuated as the head 53 of the arm 38 rides up on the wing 43 of the cam ring 42 onto the cam surface of the Wings 4I- and 45 of the cam portions 40 and 44 respectively.

Asbefore mentioned, control of the steam valve plates I1 and I8 is had by means of the shafts 25 and 26 and their respective gears 23 and 24 which mesh with the gear teeth on the respective inner peripheries of the valve ring portions I9 and it is by these means, through their control lends 21, that the valve plates I1 and I8 are shifted to vary or adjust the point of steam cut-off and the operating position of the exhaust ports.

When it is desired to reverse the rotation of the engine the direction of steam flow through the engine is changed by means of the four-way valve 59, shown in Fig. 6, and the position of the primary camming wings 43 of the cam assemblies is switched from one side of the wings 4I and 45 to theopposite side thereof bymeans of the rack bar 54 which, by ro-tating the ring gear 5I relative to the shaft 3, causes the gears 60 to turn the key shafts 49 so as to swing the keys 41 in the apertures 48 in the -wing-s 43 and thus move the camming ring 42 relative to the collar portion 40.

Thus when swung to reversed position, the primary camming wings 43 will be in a position to cam the levers 38 outwardly when the cam as- .f

semblies are rotating in the opposite or counterclockwise direction, when viewed as in Fig. 3. Therefore, since the outer curved surface of the camming wings 4i and 45 are of a length proportioned to permit the piston 8 to pass completely through the gates I0, the gates Will be automatically operated in proper relation when the engine is running in a reverse direction.

'I'hus it will be seen that my improved rotary engine is readily reversible by simply turning the four-way steam valve 59 and by manipulating the rack 54, it being understood, of course, that the gates 64 which control the auxiliary exhaust ports 62 will be arranged to be simultaneously shifted so lthat the ports at the entering ends of the cylinder-segments will be closed and the ports at the leaving ends of the cylinder-segments Will be opened.

The main advantages of my improved engine reside in the simplicity of the construction and in the arrangement whereby the vcontrol means for actuating the gates and for controlling steam supply and exhaust are housed within the engine casing, thus minimizing exterior moving parts and facilitating the arrangement of the control means so that a single lever may be used to 4control both the direction of steam flow through the engine and the shifting of the gate control cams for the reversing operation. Another advantage of my improved rotary steam engine resides in the construction and arrangement of the gateoperating cams lwhereby a single cam assembly mounted on the main driven shaft may be utilized for both forward and reverse rotation of the driven shaft, thus simplifying the engine construction and minimizing the number of camming elements required to effect a completely reversible operation.

Another advantage of my invention is found in the arrangement of steam supply and exhaust.

passages so that the two may be readily interchangeable and further in the arrangement whereby steam supplied into the segment-shaped cylinders for the power impulse is led to and discharged from the face of the piston, thereby utilizing both the expansive and reactance forces in the steam. Another advantage is found -in the construction and arrangement of the steam valving discs located on the inside of the engine and coacting directly with the driven fly wheel 2 whereby the number of valving parts are minimized and whereby either manual or automatic control is facilitated.

A further advantage resides in the shape and construction of the gates which provide the cylinder heads of the segment-shaped cylinders into which the peripheral channel 1 of my engine is divided, which construction automatically provides compensation for wear on both the abutting ends of the gates and on the sides of the same.

A still further advantage of my improved engine resides in the shape and construction of the engine casing wherein the central portions of the two half-sections making up the casing are bellshaped so as to minimize expansion in the radial direction and thereby obviate binding on the pistons. Further advantages of my improved engine reside in the arrangement whereby theentire engine is surrounded by a jacket linto which the exhaust steam is discharged, the provision of such a surrounding jacket serving not .only to keep the engine and its operating parts warm for more eicient operation, but also providing a means lfor carrying lubrication `to the various moving parts, such lubrication 4being supplied by oil entrained in or carried by the exhaust steam. The presence of the surrounding jacket also provides a means for recovering lubrication oil which will tend to settle to the bottom of the jacket where it can be readily removed.

Although but one specific embodiment of this invention is herein shown and described, it will be understood that details of the construction shown may be altered or omitted without departing from the spirit of this invention as defined by the following claims.

I claim:

1. A rotary steam engine comprising a rotatable shaft, a crank wheel fast on said shaft, a plurality of piston `members fast on the periphery of said crank Wheel, a casing surrounding said crank wheel and pistons and having vopposed axial `openings through which said shaft extends, said casing having anannular channel peripherally surrounding said crank wheel and Within `20 which said pistons fit and travel, angularly spaced retractible gates arranged to vdivide said channel into closed angular segments, each vof said pistons having a pair of steam passages therein respectively opening from opposite end rfaces of the piston and each leading therethrough and through said crank wheel to an opening in the margin yof a respective side of ysaid crank wheel, #and said casing having lan rannular steam channel -on each side of said crank wheel adjacent the margin thereof., Vsaid steam channels .each having angularly extending and spaced port openings positioned to register with the path of said crank wheel passages, Vadjustable valve kmeans arranged to vary gradually the angular location of the cut-oil' of said ports, and means to retract and vthen close Isaid gates to permit said pistons to pass the same as Aeach lof said pistons reaches a gate position during rotation of said crank Wheel.

2. A rotar-y steam lengine compri-sing a rotatable shaft, a crank vwheel fast on said shaft, a plurality of piston membersI fasten the periphery of Asaid crank Wheel, a casing surrounding `said crank Wheel and pistons and having opposed axial openings ythrough which said'shaft extends, said casing having ran annular channel periphverally surrounding said crank `wheel .and within which said pistons t andtravel, angularly spaced retractible gates v,arranged to :divide said lchannel into closed angular segments, each aof said pistons .having `a pair .of .steam passages itherein respectively opening .from opposite .end `faces of the piston and each lleading therethrough vand through said crank Wheel to an .opening in the margin of a respective side of said crank wheel, and said .casing Ahaving an v'annular vsteam channel on each side :of said crank wheel adjacent 'the margin thereof, said steam .channels Veach havingangularly extending and spacedy port openings positioned to register with the path .of said crank wheel passages-avalving ring'disposed on each sidevof said crank'wheel Vbetween said vpor-ts and said crank wheel, said `valving rings each having vports therethrough of substantially `the ysame .size .as Aand vregistering avith .said steam channel ports, 'means to :adjust ,said .valv- -ing rings angularly relative "to said .casingand said steam channel ports to vary the angular :position of the cut-'off 'of said :steam `chan-nel ports, and means' to retract :and then .close v'said gates to permit said pistons to passithezsame'as.each of said pistons reaches .a k,gate `position lduring rotation :of 'said crank wheel.

3. vIn a rotary ,steam -engine `a crank wheel 7.5

having a continuous annular rim portion, and a plurality of angularly spaced piston members fast on the periphery of said rim portion, each of said piston members having a steam passage therein opening from an end face of the piston and leading therethrough and through the rim portion of said crank wheel to an opening in the margin of a side wall of said rim portion, a casing surrounding said crank wheel and having a continuous annular channel around the periphery thereof within which said pistons i'lt and travel, said casing having an annular steam channel in its side wall adjacent the margin of said crank wheel and a plurality of angularly spaced annularly extending ports leading therefrom to the steam passage in said crank wheel, a valving ring disposed between said steam channel ports and said crank wheel and having angularly spaced ports therethrough of substantially the same size as and registering with said steam channel ports, and means to adjust said valving ring angularly relative to said casing to vary the angular position of the cut-off of said steam channel p orts.

4. In a rotary steam engine a crank wheel having a continuous annular rim portion, and a plurality of angularly spaced piston members fast on the periphery of said rim portion, each of said piston members having a steam passage therein opening from an end face of the piston and leading therethrough and through the rim portion of said crank wheel to an opening in the margin of a side wall of said rim portion, a casing surrounding said crank wheel and having a continuous annular channel around the periphery thereof within which said pistons t and travel, said casing having an annular steam' channel in its side wall adjacent the margin of said crank wheel and a plurality of angularly spaced annularly extending ports leading therefrom to the steam passage in said crank wheel, a valving ring disposed between said steam channel ports and said crank wheel and-having angularly spaced ports therethrough, a shoe on the outer face of said valving ring at the end of each of the ports therein and arranged to t into the respective steam channel port, said steam channel ports each having a groove in each of its annularly extending oppositely facing margins arranged to slidably and interlockingly receive a respective shoe, and means to adjust said valving ring angularly relative to said casing to vary the angular position of the cut-off of said steam channel ports.

5. A rotary steam engine comprising a rotatable shaft, a crank wheel fast on said shaft, a plurality of angularly spaced pistons on the periphery of said crank wheel, a casing surrounding said crank wheel and having a continuous annular channel surrounding the periphery of said crank wheel, said pistons being arranged to fit into and travel along said channel during rotation of said crank wheel and said casing having central lateral openings through which said shaft extends, angularly spaced retractiblel gates extending into said channel through the side walls of said casing and dividing said channel angularly into closed segments, and means to open and close said gates as each of said pistons passes a gate position, said gates each comprising a pair of fiat-sided plates opposed and abutting end to end within said channel and having their sides converging toward the abutting ends, one of each pair of said plates having a tongue extending along its abutting end and the other having ay complementary groove on its abuttingiend to receive said tongue.

6. In a rotary steam engine of the class described having a rotatable driven shaft, a gate operating cam comprising a collar xed to saidv shaft and having angularly spaced radial wings projecting from keach end, the wings of one end being in angular registry with the wings of the opposite end, and all said wings having arcuate ends and side edges radial with respect to the driven shaft axis, a cam ring journalled on said collar between the end wings thereof and having radial wings with the same angular spacing as said collar wings, said cam ring wings having arcuate ends of less arcuate length than said collar wings and side edges diverging therefrom toward said collar, and means to shift said cam ring angularly with respect to said collar to shift the cam ring wings from one side to the other of the said collar wings.

7. In a rotary steam engine of the class described having a rotatable driven shaft, a gate operating cam comprising a collar fixed to said shaft and having angularly spaced radial wings projecting from each end, the wings of one end being in angular registry with the wings of the opposite end, and all said wings having arcuate ends and side edges radial with respect to the driven shaft axis, a cam ring journalled on said collar between the end wings thereof and having radial wings with the same angular spacing as said collar wings, said cam ring wings having arcuate ends of less arcuate length than said collar wings and side edges diverging therefrom toward said collar, and each of said cam ring wings having a rectangular opening therein, a key fitted into each of said wing openings and having an operating shaft extending through and journalled in an aperture in a respective collar wing at one end of said collar, a ring 4gear free on said driven shaft at said one end of said collar, a gear on the outer end of each key'shaft and meshed with said ring gear, and means to rotate said ring gear relative to said driven shaft whereby said keys will rotate to shift said cam ring.

8. A rotary cam comprising a driven shaft, a collar fast on said shaft, a ring loose on said collar, and an end plate secured against one end of said collar, said collar having a radially projectmg wing at its other end and said ring and plate each having a radially projecting wing, all said wings being in arcuate registry and of the same radial length and having arcuately curved end surfaces, said collar and end plate wings having side edges extending radially with respect to the axis of said driven shaft, and said ring wing having an end surface of less length than the other wings and side edges diverging from its end toward said driven shaft, and means to shift said ring angularly relative tov said collar to throw the ring wing from one side edge to the other of collar and end plate wings.

9. A reversible rotary cam comprising a driven shaft, a collar fast on said shaft, a ring loose on said collar, and an end plate secured against one end of said collar, said collar having a radially projecting wing at its other end and said ring and plate each having a radially projecting wing, all said wings being in arcuate registry and of the same radial length and having arcuately curved end surfaces, said collar and the end plate wings having side edges extending radially with respect to the axis of said driven shaft, and said ring wing having an end surface of less length than the other wings and side edges diverging from its end toward said driven shaft, said ring Wing having a rectangular opening therein, a key fitted into said opening and having an operating shaft extending through and journalled in an aperture in one Of the other wings, said key and ring Wing aperture being arranged to cause lateral shifting of said ring wing relative to said key operating shaft upon 

